To get to Saldang is simple, if not exactly easy. You walk. The nearest airport, many days away by foot, is a rough dirt strip at an altitude of about eight thousand feet. It sits on the side of a Himalayan mountain in the Dolpo district of northwest Nepal, on the border with Tibet. Heading north from the village of Juphal, a labyrinth of small houses on a steep slope, you encounter a place where fossil fuels are not part of daily life. In much of the region, there are no roads. Horses, mules, and yaks—and men, women, and children—carry goods on trails.

One autumn day, the Nomads Clinic, a medical-service trip, pilgrimage, and adventure expedition, set off from Juphal with six riding horses, and fifty pack mules laden with a month’s worth of food, cooking equipment, camping gear, and clothing. Six duffels were stuffed with medicine and medical equipment—asthma inhalers, deworming pills, vitamins, analgesics, antibiotics. Others held hundreds of solar lights, toothbrushes, sunglasses, and reading glasses, to be given away. It was the 2015 edition of a mobile clinic that Joan Halifax, a seventy-three-year-old American teacher of Zen Buddhism, has been coördinating since the nineteen-eighties, to provide medical care in places where there is little or none.

This year, after the earthquake in Nepal, Halifax contemplated scrapping plans for the trek to Dolpo. But she considers poverty and lack of resources to be an ongoing disaster in Nepal, and she decided that there was no reason to neglect Dolpo, which is as materially poor as it is culturally rich. (In the meantime, she organized Kathmandu-based earthquake relief efforts from afar.) Our group included a doctor, four nurses, and a nurse practitioner from North America; a young lama, and a Nepali nurse born in Saldang; a German acupuncturist; and an amchi, or practitioner of Tibetan medicine. There were also a thirty-year-old, record-breaking mountaineer named Pasang Lhamu Sherpa and her husband, Tora Akita, a physical therapist from Kathmandu; a number of Westerners; and Nepali mule men, horsemen, cooks, guides, and translators.

The first day, the caravan travelled north through fields where wild hemp and pomegranate trees were growing on a slope that descended to the Tarap River. The second day, we continued through groves of wild walnuts and small stands of bamboo. The third day, there were apricots hanging on gangly young trees along the hillsides and cliffs. The fourth day, the terrain became more arid, and the plant species fewer and more sparsely distributed. We climbed high above the river and then, by a roaring waterfall, found the riverbed again. Finally, at an altitude of almost twelve thousand feet, we arrived at Lake Phoksundo, which is sacred to locals and is the approximate turquoise shade of a Las Vegas swimming pool. (Photographs of it look badly manipulated.) We were now in upper Dolpo, on the southern rim of the Tibetan plateau, one of the highest, harshest inhabited areas on earth.

The trail to the lake passed through Ringmo, a village of two-story stone houses. Men walked down from the heights with huge loads of hay on their backs. Along the main path, an old woman dug tiny potatoes out of the soil with her hands. Later, we saw men behind wooden plows pulled by yaks, the shaggy, humpbacked beasts that roam everywhere in upper Dolpo, and whose milk is used to make yogurt, cheese, and butter. The butter is stirred into tea and burned in lamps. Women used handmade wooden rakes, and after threshing the barley they tossed the results into the wind, letting the chaff blow away and the grain fall back into baskets.

Before the Chinese invasion of Tibet, in 1950, the herds of yaks, horses, sheep, and goats were larger, and people moved freely between Dolpo and Tibet, where salt mined from the dry bed of an ancient sea was traded for grain, which the high plateau lacked. But, as China clamped down on the border, the Dolpo population’s longtime use of Tibetan winter pastures ended. And the market for Tibetan salt was undermined by subsidized imports from India.

The residents of lower Dolpo, some Hindu and others Buddhist, mostly speak Nepali, and greeted us with “Namaste” (“I bow to you”). Past Ringmo, in upper Dolpo, the principal language is Tibetan, and the greeting is “Tashi delek,” meaning something like “blessings and good luck.” Both Buddhism and Bon, a religion indigenous to Tibet, are practiced there. The landscape is studded with gompas, fortresslike structures combining the functions of library, seminary, and temple. Some date back several hundred years, and many have a pair of seated golden deer on their entry gates. The lama accompanying us said that deer were among the first creatures to listen to the Buddha.

In the course of nearly four weeks, our group walked between four and ten hours on the days when clinics were not held. We followed a steep oval circuit through the mountains, covering about a hundred and forty miles. A few nurses were stationed in the towns in Dolpo, but we heard that they never stayed long, and for most inhabitants the nearest hospital was too far away. There were five clinics, and we treated almost seven hundred people, out of an estimated five thousand residents of the upper Dolpo region.

The first clinic was set up at Lake Phoksundo. Patients came in with digestive troubles, infections, and, often, strained necks and sore joints from a lifetime of carrying big open baskets full of apples or firewood or household goods.

Alcoholism is widespread in Dolpo, and the few tiny shops we saw offered Chinese liquor among their meagre wares, though most people drank homemade raksi, a hard liquor made from grain. One morning, we went to the Bon monastery, on a promontory above Lake Phoksundo, where a smiling, red-clad monk showed us the four-hundred-year-old rooms, with murals of lamas on horseback and painted Buddhas in the lotus position—the colors were blue, green, yellow, red, and white, like those of the prayer flags fluttering in the sunshine. Then he apologized for being drunk. The abbot told us that the monastery had been built to protect the blue sheep, creatures related to mountain goats and ibexes, from hunters who would drive them down the mountains and then herd them over the bluff to their death.

Occasionally, during the two days we were camped there, we gazed across the blue water at the trail that awaited us on the steep hillside beyond. It looked as though someone had casually scratched it with a stick, the way you might draw on a map with a pencil, not like something you should trust with your life. The term “trade routes” may summon up visions of broad paths, but thousand-pound yaks can traverse faint, canted trails the width of your outspread hands.

From Phoksundo, Saldang was still a week away, over one pass that rose to more than 17,600 feet and another to about 16,700 feet. Our sirdar, or head guide, noted that years ago there was a great deal of ice at the highest pass, but we found only a retreating mass of snow in a shadowy stretch of the path. We all got used to moving steadily along, amid the scree, the dust, the ruts, the trails built to hang out over the abyss, the slippery slabs of rock, the staircases of irregular stones, the rickety bridges of logs or old wood patched with flat stones. There was rarely a phone signal in the regions where we ventured, though at one of the high passes the young Nepali men in our expedition lined up to make calls, looking like regulars at a bar three miles high, scoured by wind, with hundred-mile views.

Between the two passes lay Shey Gompa, the ancient monastery of the Crystal Mountain, one of the holiest peaks in Tibetan Buddhism. The old abbot told us about a predecessor, hundreds of years earlier, who had first recognized that the mountain was sacred, and about the ability to recognize the sacred as a special gift or talent. Tenzin Norbu, the outfitter for our expedition, told us that prayers here had several thousand times the power they have elsewhere. Inside, we saw ranks of butter lamps burning before golden Buddhas on an altar flanked by gaily painted shelves of sacred texts bound in bright silk. Outside, we saw people who had walked there from fuel-starved Saldang to gather dung from the ample supply that passing mules provided.

The abbot welcomed the Nomads Clinic into the temple, and locals asked the doctor and the nurses to treat wounds, address pains, listen to stories. The first evening, a horseman brought in a comrade, who was too sick to walk. “He was such a beautiful man, and he was almost dead when I first saw him,” the doctor, who diagnosed a severe kidney infection and treated him with antibiotics, said. The man, who was in his early forties, had a drawn, sun-darkened face, a faint mustache, the high cheekbones of most of the Nepalis in the region, and a thick coil of crimson strands of wool around his braided black hair. He wore camo-patterned tennis shoes. The next day, he was back on his feet, lingering outside the monastery to make contact with the doctor and the nurses coming from meditation inside.

The medical staff treated sixty-five people in Shey, mostly nomads from the tents on the river plain below the monastery and beyond. They shared their complaints with smiles and good grace. Dolpo residents wandered into camp throughout the trip: a pregnant woman with infected breasts; a group of children who had impetigo, escorted by their anxious mothers. Some conditions were curable. Some were not. To a man with a broken pelvis and a woman with a broken back, we could offer only painkillers and advice. The morning after the clinic, we packed up and set out again.

Joan Halifax started the Nomads Clinic in 1980, and it has grown by increments in the decades since. She goes by the Japanese honorific roshi, or teacher, and has made annual trips to Nepal and Tibet for thirty-five years. She has circumambulated the 21,778-foot Mt. Kailash, another of the sacred peaks, eight times, and has wandered far into Tibet and into the mountains of Nepal, where she learned practical things, such as how to give a horse an enema. (She oversaw one for a sick gelding on the 2015 trip.) She has been inside many of the region’s monasteries, and she recently visited one treasure house in which the ancient skull of the monastery’s founder lived on as a kapala, or ritual cup.

In Nepal, relics owned by monasteries have been stolen, and sold on the black market in Kathmandu, China, and elsewhere; some Dolpo gompas have taken to burying their treasures. In 2011, the household of a friend of Halifax’s—in Humla, a district west of Dolpo—was robbed of its family gods, sacred statues that had been with the household for many generations. Halifax used social media to help track down the figures. The main statue, a fourteenth-century Tibetan bronze medicine Buddha—the Buddha who presides over spiritual and physical healing—had reportedly been on the black market for two hundred and twenty-five thousand dollars. The robbers, known as the Karnali Tigers, were caught and imprisoned in Humla. “I visited the prison,” Halifax told me. “A true hellhole.” (Last month, robbers raided the monastery at Shey Gompa, beating up the caretaker and stealing several statues.)

“The idea of just tromping around the mountains never appealed to me,” Halifax said. “I’d rather stay home on my zafu”—her meditation cushion—“and study the dharma.” Halifax’s medium is psyches, communities, and social systems. Through her many activities—teaching, bridging cultures with such projects as the Nomads Clinic, drawing people to social activism and a contemplative life—she can be imagined as a weaver or a sculptor, conjuring new forms out of her raw material: people and groups. To intervene in individuals’ lives takes confidence, which she has in abundance.

In Dolpo, Halifax wore a black robe with a white hat, layers of black down vests and coats, and a pair of Merrells. Most of the time, she travelled astride a calm, compact white horse. You could consider riding less demanding than walking, but if you got on a horse in that terrain you continually encountered the abyss and your own mortality. “I remind myself that the horse wants to live,” Halifax often says. She dismounted during the most treacherous passages, with the hovering presence and sometimes the firm hand of her longtime attendant in Nepal, a lean, quiet Humla man named Buddhi. Halifax has osteoporosis, and a fall could be serious, but she’s chosen risk over limits.

In many of Dolpo’s holy places, Halifax was received as an honored guest, and although she says that she doesn’t enjoy the attention and the gifts, she accepts them as acknowledgments of the ties between ancient Buddhism and the young Buddhism of the West, and as an honor to a woman in a male-dominated tradition. At each temple, gossamer silk scarves were draped around her neck—white, saffron, turquoise, red. Bows of acknowledgment were performed and formal speeches were made. She was seated in state while chants were recited.

Halifax was brought up in Coral Gables, Florida. An illness left her blind from the ages of four to six, and those two years, she said, led her to discover that she had an inner life: “The blessing that comes from catastrophe has been a theme in my life.” She recovered, raised a condemnatory eyebrow at débutante balls—her right eyebrow still does a lot of critical work for her—and vowed to escape. Her first step was college in New Orleans, where she participated in sit-ins and civil-rights marches. Afterward, she became a research assistant to the musicologist Alan Lomax, at the Bureau of Applied Social Research, at Columbia University.

She rode many of the waves of upheaval of the nineteen-sixties and seventies, and had a knack for landing where events were getting interesting. She went to Paris in 1968 to work at the Musée de l’Homme, arriving just in time to witness the student uprising that became a general revolt. She travelled to Algeria at the behest of the Algerian Ambassador to France, who hoped she could figure out why former revolutionaries in one neighborhood had such a high suicide rate. Her conclusion was that, when the war was over, “there was no one external to fight,” and the conflict went inward.

In Algeria, she also met the Black Panthers Stokely Carmichael and Eldridge Cleaver. “When I saw Eldridge in Algiers, I was taken aback,” she recalled. “I was sitting in a café near the ministry of tourism, and there he was, the Black Panthers’ minister of information, strolling down the street, a fugitive and free.” Algiers, she told me, was filled with spies, intrigues, music, dance, “and a sense of revolution and possibility.” A man whose advances she rebuffed reported her as a spy, and she did a brief stint in an Algerian jail.

Most lives have lulls. Hers so far hasn’t. “I just lived as though my hair were on fire,” she said. Halifax spent much of 1969 among the Dogon tribe of Mali, whose ritual life made her wonder what new rites might be available to Westerners—especially the dying, for whom “spiritual and psychological issues leap into sharp focus,” she wrote in her 2008 book, “Being with Dying.” In 1972, Halifax married the Czech psychiatrist Stanislav Grof and joined his experiments in psychedelic drugs as therapeutic tools for the dying. (They divorced five years later.) Sick with hepatitis, which she contracted in Africa, and generally in crisis, she turned in earnest to Buddhism.

In 1975, Halifax became a student of Seung Sahn, an innovative Korean Zen master based in Providence, Rhode Island, whose methods were influenced by Korean shamanism. She took up the tough Korean version of Zen, which involved doing a hundred and eight prostrations (think pushups, with devotion) before daily meditation at 5 a.m. During her Buddhist training, she was ordained by Seung Sahn and then by Thich Nhat Hanh, a Vietnamese Buddhist teacher and antiwar activist. Through Nhat Hanh, Halifax said, she was “inspired by the relationship between social action and contemplative life.” Halifax also trained with Bernie Glassman, who taught what is sometimes called “engaged Zen.” Participants in his “street retreats,” instead of withdrawing into a sanctuary, lived as homeless people.

In 1990, Halifax founded the Upaya Zen Center, in Santa Fe, New Mexico, a residential community with daily meditation, weekly talks, and a busy schedule of meditation retreats, workshops, and seminars. In the spirit of Glassman, Halifax has trained disciples who work with the homeless, with prisoners, and with the dying. She is still the abbess at Upaya, although she’s away about half the year. In 2015, she has been to Hawaii twice, once to teach about death and dying with Ram Dass, and once to teach about compassion; to Japan, to lead a program on temples and shrines; to Costa Rica, to conduct a seminar on Buddhism. She has also given talks this year in Singapore, New York, Washington, D.C., San Francisco, and Louisville. A few months after the Nepal odyssey, she flew to Bangalore, for a conference of the Mind and Life Institute, an organization that blends scientific and contemplative approaches to the study of the mind (Halifax sits on the board). Zen gives her the ability to be at home anywhere.

Halifax was once a great beauty, with fierce blue eyes and long chestnut hair. She shaved the hair off in 1996, and can describe the moment when, in Santa Fe, turning onto Gonzales Road from Cerro Gordo Road, she realized she’d been conditioned to think that “pair bonding” was an inevitable and necessary part of her life. She took up celibacy and independence—but not solitude. She calls herself an introvert with a personality, but she responds to e-mails in a flash and uses social media constantly.

She travels with Noah Rossetter, a thirty-year-old Zen priest with a lighthearted disposition, a knack for technology, and the steadiness to keep the many parts of her life from tangling up. The two amuse each other with banter and by occasionally singing snatches from operas. They could be mistaken for a comedy team: in camp at Lake Phoksundo, when someone asked about what to do with “number one and number two,” Halifax answered, “Be one with nature,” and Rossetter added sternly, “Push duality in the hole.”

Halifax keeps in touch with many dying people, and also with film stars, affluent donors, scholars of consciousness, and monastics in various traditions, including the Dalai Lama and her Zen students. She said that, after years of involvement with medical care, she sees “much suffering in the experience of Western clinicians, weighed down by the demands of their institutions—which are demands to protect the institutions from being harmed.” She takes the clinicians she recruits “to a place where cure isn’t necessarily possible but care is,” and said that the experience of working with patients on the trips was “a kind of grace or blessing.”

On the afternoon of Saturday, April 25th, a temblor, as Halifax put it, “tore the heart out of Nepal.” It was followed by an aftershock in May. Together, they killed an estimated nine thousand people; shut down the tourist industry; smashed about half a million homes, displacing a population of about three million; triggered avalanches that cut off high-altitude villages; and, in Kathmandu, crumbled many ancient religious sites. The quake was centered in Gorkha, a district in the middle of Nepal.

When Halifax heard the news, she began checking in on Facebook with everyone she knew in the area. Her mountaineer friend Pasang Lhamu Sherpa, who guides climbs of major peaks around the world, was with a client near Base Camp on Mt. Everest, where the quake prompted an avalanche. Many people fled, but Pasang went toward the avalanche, in the futile hope of finding survivors; nineteen people died. Pasang dispatched her client, and got a helicopter ride to Kathmandu, where she joined her husband, Tora Akita. She announced her safe arrival on Facebook, and on April 30th asked friends and family for support—manpower, food, blankets, tents—as she and Tora headed into the wreckage.

A few years ago, one of Pasang’s clients introduced her to Halifax, and the two women took to each other. “What I recognized in Pasang,” Halifax recalls, “is a quality that I had when I was her age—incredible drive and this feeling that we as women were born for a mission that is compassion-based. I was meeting a person who had very few contrivances, who had been as a child exposed to a lot of suffering, and had become a role model for women at a global level.” Pasang and Tora joined Nomads Clinic trips in 2013 and 2014.

The husband and wife look a bit alike: Tora has a wing of black hair over his brow, Pasang has dark hair to her waist, and both have expressions of self-effacing kindness. Tora is unusually tall for that part of the world, and is slender in a way that in a woman might be called willowy. Pasang, at five feet seven, is tall, too. At first, you notice only that she’s beautiful. Later, you realize that her rounded limbs and her torso are tremendously powerful.

After the earthquake, the three became the core of a disaster-relief team. Halifax raised a quarter of a million dollars; Tora was the central coördinator of a shifting, growing group of volunteers and supplies; and Pasang went deep into the disaster zones. In Kathmandu, Pasang and Tora worked with Thomas Mathew, an erudite fifty-year-old Indian man, to organize help. With dozens of volunteers, they directed convoys of trucks, moving forty tons of rice at a time; found sources for salt, lentils, and cooking oil in volume; and had tarps trucked in from India. Tora was sometimes so busy that he talked on two phones at once, and he went on many of the relief missions that headed out in the middle of the night. Pasang coördinated the efforts of drivers, donors, volunteers, porters, and locals. On the scene, she made sure that supplies were distributed equitably, and commanded village chiefs and truck drivers alike. For a Nepali woman, it was an unlikely role. Mathew recalled, “She has the authority. She has the voice. It comes from the gut.”

As a high-altitude mountaineer, Pasang had often hired helicopters and knew many of the pilots who took climbers and adventurers around Nepal. She worked with them to deliver supplies. In a relief effort for Laprak, one of the Gorkha villages that were cut off by landslides, she organized three hundred local men as porters to carry food and tarps, enlisting them in disaster relief while arranging for them to be paid out of funds that Halifax had raised. An estimated twenty thousand Nepalis a year are trafficked, and, in the chaos of the earthquake’s aftermath, there were more opportunities to seize victims. Pasang began giving talks in the refugee camps about how to protect oneself. When no one came, she announced that she was giving away sanitary napkins, and delivered her speech when the women arrived.

On the Nomads trip, during the steepest passages and at the highest altitudes, even those of us who had done some training approached the limits of our capacity. Almost everyone—excluding Pasang and the tough young Nepali men—found that walking uphill at the highest elevations left a person panting. Pasang’s energies remained essentially untapped by any challenge—a ten-hour walk, a five-thousand-foot gain in altitude, a freezing night in a tent, air so dry that fingers cracked and noses bled. When a young woman sprained her ankle, Pasang was the first person on the scene. When dinner was ready, she served it. When the women’s clinic was held, she was the translator and the doorkeeper. She carried rescue equipment in her big day pack, watching over us like a shepherdess.

Pasang was born in 1984 in a village about thirteen thousand feet high, and grew up in the town of Lukla, often called the gateway to Mt. Everest. As a child, she resolved that she would climb the mountain. Her father died when she was a toddler, her mother when she was fifteen. By the time she was eighteen, she was training in a male-dominated Nepali mountaineering school while supporting her younger sister. Like Halifax, she was supposed to have one destiny but made another. In her community, she said, women were meant to marry young and raise children. “They think I’m doing something wrong,” she said.

In August, 2006, she became the first Nepali woman mountaineering instructor, and the first woman to ascend the 24,117-foot Nangpai Gosum II. Not long afterward, she was injured while climbing, when her handhold on a cliff crumbled. She swung hard on the rope anchored below her, smashing her hip. The injury made it difficult to do the lateral moves that climbing requires.

Almost a year later, a Japanese team doing cleanup on Mt. Everest invited her to climb the mountain from the less-traversed, Chinese side. She scraped together the money for boots, crampons, and the rest of the gear, but her injury got worse. Someone recommended a Japanese physical therapist in Kathmandu. It was Tora, whose father is Japanese and whose mother is Nepalese. “He was so young, so handsome,” Pasang told me. “And he’s, like, ‘You shouldn’t climb.’ I’m, like, ‘No, I want to climb.’ He treated me four days. Every day three hours, and then—gone, the pain was gone. He kept saying, ‘You shouldn’t go.’ ” She went.

When she was on Mt. Everest, her injury reasserted itself. “I couldn’t climb,” she said. “I had to grab my leg and put it down, grab my leg and put it down.” She did exercises that Tora had taught her, and made the climb on ibuprofen and will power. She returned in dire need of physical therapy. In gratitude for Tora’s help, Pasang offered to take him trekking. He asked to see her home town in the Himalayas. The patient-caregiver relationship became a friendship, and the friendship became a romance. They married in 2010. Mathew remembers that Tora and Pasang wore traditional Sherpa clothing at the wedding. Marriage didn’t interfere with her mountaineering. She said, “I wanted to show and tell people, If you really want it, it doesn’t matter if you’re married or you’re mothers.”

Last year, with two other Sherpa women, Pasang organized a Nepali women’s ascent of K2, the mountain in Pakistan that is nine hundred feet shorter than Mt. Everest but far more dangerous. About one in ten climbers dies in the attempt to climb K2. Its violent weather offers climbers smaller windows of time to summit, and chunks of ice fall off the face that climbers must scale. Getting up its couloir, or ice gully, known as the Bottleneck, is a brutal ordeal. Only fifteen women had climbed K2, and, despite the number of Nepalese Sherpas in high-altitude mountaineering, no Nepali women had made the ascent until Pasang and her companions did, on July 24, 2014. Pasang told me that everyone had told her that K2 was a killer, but “I just wanted to feel what this mountain is.” In a picture taken at the summit, she wears a red snowsuit and huge boots that make her appear bulky, a little unreal, like a Transformer toy, but her helmet and oxygen mask are off, and she looks bold and free.

Twelve days after we started, we came down from the second pass, Sela La, to Saldang. To a visitor, the thirteen-thousand-foot-high settlement looks like a picture from a fairy tale or a volume of “The Arabian Nights”—nothing extra, everything emblematic. The stone houses, plastered the same color as the dusty slopes, are surrounded by small, terraced barley fields and rough stone walls, sometimes enclosing a horse or a yak or a barking mastiff. Their flat roofs, reached by ladders made of logs notched with steps, are fringed with the grayish brush that fuels the sheet-metal stoves inside. White prayer flags snap in the strong afternoon wind, and stupas, three-tiered mud towers to the spirit, rise from the ridges.

The clinic was set up in the school. People came dressed in traditional clothing, the women and girls wearing ankle-length tunics with kick-pleats, scarves and shawls in rich purples and hot pinks, and necklaces of turquoise and coral disks. Some of the children wore shirts emblazoned with names like Adidas; they must have come from as far away as the ocean coral. Others wore Tibetan-style sashed jackets and tunics. It was as though all the region’s color had been stripped from the eroded hills and deposited on the people.

As they waited in line, some of the men swung brass prayer wheels, and some of the women spun woollen thread on drop spindles. Children carried smaller children on their backs or played, and everyone chatted. The man with the kidney infection from Shey Gompa was among them, with the same red yarn ornament and the same black braid. He had been near death, and was now able to travel as fast as we were.

The clinic was welcomed with a speech from the school principal, in Tibetan and English, and schoolchildren danced to scratchy music emanating from speakers on stands in the dusty yard, powered by the solar energy system next to the school. There was a traditional Tibetan dance, a Nepali dance, and a theatrical pantomime performed to a mixture of music and the Dalai Lama’s voice, advocating nonviolence. The children reënacted the invasion of Tibet; those playing the Chinese carried wooden guns. A girl in a blue blouse gave a stunning performance of dying in slow agony.

Then the nurse practitioner administered gynecological exams in the only closed room in the clinic, with Pasang guarding the door. Everywhere else, families crowded into the dim schoolrooms to watch what the clinicians did, and children poked their heads in the windows, which had brightly painted shutters but no glass. The nurses gave away the last of the prenatal vitamins, but the children had already been dewormed by a visiting nurse, so they didn’t distribute the deworming pills. Long lines stretched from wherever the bodyworkers were practicing.

The doctor listened to hearts and lungs. He looked at wounds, sores, eyes, ears, throats, skin, joints. He dispensed what care he could—pain relievers, antibiotics, steroid creams, asthma inhalers, advice to stop drinking the moonshine and to quit smoking cigarettes. (Packets with diseased-lung images on both sides littered all the long-distance trails.) Later, the doctor told me that when he looked into people’s eyes with an ophthalmoscope he rarely saw a “red reflex”—the red light bouncing off a healthy retina. Instead, he saw the opacity of eyes beginning to form cataracts from long exposure to the blazing sun of the high-altitude desert.

There was too much light and yet not enough. The evening after the Saldang clinic, we visited the mother of Pema Dolma, a young nurse and Saldang native who had moved to Kathmandu and come back to trek with us. Her mother lived with Pema’s half sister, who was mute, and a granddaughter in a small, square house with one tiny window in its thick walls. The house was feebly illuminated by a slender fluorescent tube hooked up to a rooftop solar panel.

I asked Pema Dolma what her mother did for light before she got solar, seven years ago. The older woman brought out a flickering brass butter lamp. We were served butter tea, and we gave them three solar lights. The next morning, we began our return journey, heading south.

The suffix “-la” is a term of respect and affection in Dolpo: Halifax became Roshi-la, Pasang became Pasang-la, and so forth. The syllable also describes a high-altitude pass. As we descended from upper Dolpo, we looked southeast from the last pass—Jyanta La—toward Dhaulagiri, the world’s seventh-highest peak. In the white mountain ranges above the heights we traversed, snow and glaciers feed the streams that flow through these arid, stony places. The same sources water the barley and the potato fields, the livestock, the farmers, and the nomads of Dolpo, and extend far beyond it. A billion and a half people are nourished by water from the Tibetan plateau, which pours out into the Yangtze, the Yellow River, the Mekong, the Ganges, and the other legendary rivers reaching across Asia. The last river we travelled was a tributary of a tributary of the Ganges.

Throughout the region, the snow and the glacial ice are withering away. Halifax recalled a Tibetan prophecy, “When the mountains wear black hats, the world will end,” and interpreted the black hats as the peaks without snow and ice. One day, some of the clear, cold streams and rivers flowing through upper Dolpo might dry up for part of the year, or stop entirely. The people who never had coal or electricity might be forced out of this place where the butter lamps are still lit before golden Buddhas in the old painted gompas, and where the barley is harvested by hand.

During the final days of our journey, snow began to dust the hills behind us, coming lower and lower, as if the door were closing for the year on Dolpo. In the first settlement below Jyanta La, when the tumbling alpine stream had become a gentle river, we encountered the first internal-combustion engine of the trip, a motorcycle, probably brought in by helicopter. Past the agricultural valley of Dho Tarap, we returned to the world of trees: hanging gardens of birches, golden in autumn, high up the gorge of the river; tall pines with clusters of blue cones; huge cedars; wild fruit trees. Along the canyon of the rushing Tarap River, we made our way back to Juphal.